Suggestions for large turning

[William C Rogers]

I have never done a large turning. I have a piece of hickory. The tree had been on the ground for several years and I was just going to cut it for firewood. However it is fairly solid, so I thought I would try something big. I have the outside somewhat roughed. The diameter at the flange end is about 12" and about 8" at the base. Overall length about 26". The MC is still around 30% to my surprise. My questions are should I take off the lathe and let it dry for a couple of months or rough the inside and then remove. I have a faceplate on the bottom. I will setup a steady rest to do the inside. If I rough the inside I was thinking of making plug so I use the tailstock when I put the dry turning back in the lathe. Other suggestions are welcome on form or anything.

image.jpeg

As as a side note the lathe rocked when I first installed the log, but not violent as my lowest speed is 300rpm. I have added 250 lbs of sand. Also I only have 1hp, but never stalled it.

[daryl moses]

I would treat it the same as a bowl. Rough it out, leave it thick, bag it or fill it with shavings and let it dry. When dry enough finish turn and apply finish.
Good luck that piece looks promising.

[Howard A. Wilson]

Hi,
If this is the whole tree with the pith in the center, it will shrink symmetrically. There is no need to let it dry before finishing it. The bottom is almost certain to split as the radial shrinkage is greater than the tangential shrinkage. You could drill a hole in the base to let is move and then plug the hole after it is dry. The sides will not split as they can shrink to the hollow center. I turn wood not clay or metal. I enjoy the wood movement as the wood dries. You will need tools with heavy long handles to hang 26 inches off the tool rest. With my tools I can only do 9 inches before the vibration starts. Enjoy your turning

[robert baccus]

I do mostly vases and find this works. Apply endseal to the outside, endgrain top and botom and inside the lip. Leave the inside open--it is safe. Dry for a while-return,sand and finish. I forgot to mention to hollow while is damp or green--hickory turns to ironwood when bone dry.

[Reed Gray]

I don't do many hollow forms, but with bowls, anything around here on the ground for a year or three will crack twice as bad as fresh wood. I don't think I would twice turn it, just turn to finish and put several coats of finish on it, especially on the end grain bottom where cracking is most likely to occur. If I was going to twice turn it, I would seal the entire outside, or plastic wrap it, and again, lots of sealer on the end grain bottom.

robo hippy

[William C Rogers]

Thanks for the replys. This is definitely an adventure for me. Howard, thanks fo the tip drilling out the pith. That may really help. Reed, I did some checking last night and that tree has been down since 2009, on the ground in a shaded damp area. First thing I need to do is make a larger steady rest. I can only hollow about 10-11" deep with tools I have and will need to make something for deeper hollowing. I have some ideas for that. I'm thinking the finished wall thickness should be around 5/8" so I will rough to about 1" thickness. I'll need to figure out how to measure the wall thickness at the bottom since I don't have a commercial hollowing system. Not mentioned, I think I will still make a plug so I can use the tail stock to finish the outside. Once roughed I'll drill the pith out, wrap the outside with stretch wrap, seal the ends, and fill with wood chips to dry. Then after dry, finish.

[John Keeton]

William, you mentioned filling the inside with chips, but I think you will get better results if you slow the outside from drying and let the form dry from the inside. I would seal the outside with Anchorseal or some other sealant and leave the inside bare. If the form dries from the outside that surface will want to shrink and contact, but being restrained by a damp inner surface that won't contract with the outside, you have an increased risk of cracking on the surface.

Just a thought.

[William C Rogers]

Thanks John, that sounds reasonable.

[John K Jordan]

Have you seen the large turning David Marks made? His blog on it might be interesting:

http://www.djmarks.com/sensei/



JKJ

[William C Rogers]

Thanks John. I think I'll skip the water barrel. Beautiful work. The stand is something to think about as my pith is off center and might be able to turn out.

[robert baccus]

Roger what Keeton related--any moisture inside will encourage splitting. Concerning the plug just make a cone of scrap wood that will attach to your tailstock or chuck o hold it centered for finishing.